Manufacture of vanillin



Patented May 5, 1925.

UNITED STATES PATENT OFFICE.

OSKAR SPENGLER AND HUGO PFANNENSTIEL. OF DESSAU IN ANHALT, GERMANY, AS-

SIGNORS TO ACTIEN GESELLSCHAFT FUR. ANILIN FABBIKATION, 0F BERLIN.

MANUFACTURE OF VANILLIN.

ltlo Drawing.

To all whom. it may concern:-

Be It known that we, OSKAR Srnxmau: and Hrmo PmNNENs'rucn, citizens ofthe German Republic, residing at Dessau, in Anh'alt,

ucts of esters of diketone acids or of 1nesoxalic acid esters withguaicol (obtained by heating these products in4-dimethylamino-l-methylbenzene) may be converted into vanillin (compareGuyot and thy,

' Comptes Rendues de IAeadmie des Sciences, vol. 149, pages 928-938)This process of manufacture has not attained any tech nical value, themanufacture of the applied esters being-very ditficult. I

Now we have found that trihalogenmethylguaiacylcarbinol (thecondensation product of chloralhydrate with guaiacol, compare lterichteder Deutschen Chemischen (lesellschaft, vol. 56, page 982) may betransfOlll'lQdlIllO vanillin in a. very simple manner. By saponificationof this trihalogenmethylguaiacylearbinol, carboxylic acids are obtainedwhich by a suitable oxidizing process yield vanillin with good results.

The following examples serve to illustrate our invention withoutlimiting it:

1. grains of triehlormethylguaiacylcarbinol are heated in a refluxapparatus with 1400 grams of water for 24 hours. 24 grams of ferricchloride are added and the solution is boiled once more for 24 hours. Byextraction of the solution 2.5 grams of vanillin are obtained.

2. 50 grams of trichlormethylguaiacylcarbinol are boiled with 4 litersof water in a reflux apparatus for 12 hours. After addition of 75 gramsof copper acetate the solution must be still boiled for twelve hours.Then it is evaporated to 2 liters Application filed August 1, 1924.

Serial No. 729,655.

and extracted with ether. The ethereal solution contains 18-20 .grams ofyellowish crude vanillin. i

3. 50 grams of trichlormethylguaiacylcarbinol and 20 grams of copperacetate are boiled with 4 liters of Water in a reflux apparatus for 12hours, a current of air being blown through the solution. From thecololed solution the vanillin is extracted, with et ier.

4. 20 grams of trichlormethylguaiacylcarbinol are boiled in a refluxapparatus with 1 lither of Water for 12 hours. After addition of gramsof copper acetate the solution is still boiled for another 'hour. Afterthis it is heated in a closed vessel to 150 C. for half an hour. Thevanillin is extracted from the solution with ether, the yield amounts to9 grams.

5. 50 grams of triehlormethylguaiacylcarbinol are boiled with 4 litersof water, 30 grams of calcium carbonate being added. After 12 hours 75grams of copper acetate are added and the solution boiled for Qt hoursmore. The vanillin may be finished in the described manner.

If in Example 5 the calcium carbonate is replaced by the equivalentquantity of so dium acetate or sodium carbonate one obtains vanillinwith a like yield.

\Vhat we claim is, y

1. Process for manufacture of vanillin which consists in saponifying andoxidizing trihalogenmethylguaiacylcarbinol.

2. Process for manufacture of vanillin which consists in saponifying andoxidizin; trichlormethylguaiacylcarbinol.

In testimony whereof we afiix our signa tures in presence of twowitnesses.

OSKAR SPENGLER. HUGO PF ANNENSTIEL. l/Vitnesses RUDOLPH FRICKE, TVILLYSTIER.

